#!/usr/bin/env python3

class BenzCar:
    def run(self):
        print("奔驰")

class HummerCar:
    def run(self):
        print("悍马")

class SimpleFactory:
    def build_car(self, car_type):
        return eval(car_type)()

if __name__ == "__main__":
    class FutureCar:
        def run(self):
            print("未来汽车：你想象不到的样子")

    factory = SimpleFactory()
    car = factory.build_car("FutureCar")
    car.run()
